An Online Respiratory Quotient-Feedback Strategy of Feeding Yeast Extract for Efficient Arachidonic Acid Production by Mortierella alpina

Li, Xiangyu; Yu, Chao; Yang, Jianming; Wang, Zhiming; Lu, Shu-Huan

doi:10.3389/fbioe.2017.00083

Cited by 9 publications

(12 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Time courses of glucose consumption rate, lycopene production, and cell OD 600 in BR + 3 g/L YE groups are similar to the YE group (Supplementary Material), which means that addition of 3 g/L yeast extract in the biomass residue group could sufficiently provide microelement, vitamins, and nucleotides which may not exist in biomass residue. Yeast extract is identified as significant factor for producing many valuable nutrition like arachidonic acid, docosahexaenoic acid, astaxanthin, and beta-carotene (Kusdiyantini et al, 1998;Bhosale and Gadre, 2001;Quilodrán et al, 2010;Li et al, 2018). The same phenomenon is also observed in this study.…”

Section: Effect Of Wastewater and Biomass Residue Replacement On Lycosupporting

confidence: 81%

“…In addition, the contents of amino acid are different in biomass residue and yeast extract. Yeast extract is a widely used multi-functional nitrogen source in microbial fermentation industry (Li et al, 2018). Though the content of nitrogen and phosphorus in biomass residue are lower than in yeast extract, the species of amino acid shows no difference in both the two nitrogen sources.…”

Section: Composition Analysis Of Yeast Extract Biomass Residue and mentioning

confidence: 99%

See 1 more Smart Citation

Continuous Self-Cycling Fermentation Leads to Economical Lycopene Production by Saccharomyces cerevisiae

Wang

Li²,

Yu³

et al. 2020

Front. Bioeng. Biotechnol.

Self Cite

View full text Add to dashboard Cite

The economic feasibility and waste treatment problem are challenges to the industrialization of lycopene production from Saccharomyces cerevisiae. In this study, fermentation wastewater, biomass residue, and residual D-galactose are recycled for lycopene production. Results show that when fresh water is totally replaced by wastewater, lycopene titer attains 1.21 ± 0.02 g/L, which is 14.2% higher than the fresh water group (P < 0.05). An 80% replacement ratio of yeast extract by biomass residue causes no significant difference to lycopene production while 100% replacement ratio significantly lowers lycopene titer compared with the yeast extract group. Then, a novel fermentation medium containing wastewater and biomass residue with supplementing 3 g/L yeast extract and D-galactose is used for lycopene production. Lycopene titer increases 22.4% than the traditional fermentation in shake flasks (P < 0.05). Continuous self-cycling strategy using wastewater and biomass residue was tested in shake flasks. The mean lycopene titer of the first five recycles shows no significant difference with the start batch. Scaling up to 70 L fermenter, the mean lycopene titer attains 5.88 ± 0.15 g/L in three recycles, which is 22.25% higher than the start batch (P < 0.05). Economic analysis shows that the lowest unite product cost is achieved when four recycles are accomplished, which is 29.6% lower than the traditional fermentation while the chemical oxygen demand decreases 64.0%. Our study shows that continuous selfcycling fermentation process for lycopene production is feasible for the first time. The comprehensive utilization of wastewater and biomass residue from lycopene production by S. cerevisiae and achievement of high lycopene titer will hopefully accelerate industrialization of microbial production of lycopene.

show abstract

Section: Effect Of Wastewater and Biomass Residue Replacement On Lycosupporting

confidence: 81%

Section: Composition Analysis Of Yeast Extract Biomass Residue and mentioning

confidence: 99%

Continuous Self-Cycling Fermentation Leads to Economical Lycopene Production by Saccharomyces cerevisiae

Wang

Li²,

Yu³

et al. 2020

Front. Bioeng. Biotechnol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Additionally, intracellular availability of oxygen plays a key role in CA biosynthesis, considering the oxidation steps catalyzed by the enzyme clavaminate synthase [48]. According to Li et al [49], the RQ values close to 1 observed in both reactors during the first hours of cultivation (see Figure 3b), indicate a balanced metabolism consistent with the aerobic oxidation of glycerol and glutamate as carbon sources present in the media. During the fed-batch operation the appearance of phosphate limitation led to a rapid decline in the RQ showing the increase of oxygen demand in this stage.…”

Section: Discussionmentioning

confidence: 58%

“…These results suggest the RQ as an additional parameter to consider in S. clavuligerus cultivations for CA production in connection with the macromorphology and the hydrodynamic conditions. In this regard, an online RQ-control approach could be applied to S. clavuligerus as a strategy to promote changes in carbon fluxes and therefore, the synthesis of the desired products [49,53].…”

Section: Discussionmentioning

confidence: 99%

Characterization of the Metabolic Response of Streptomyces clavuligerus to Shear Stress in Stirred Tanks and Single-Use 2D Rocking Motion Bioreactors for Clavulanic Acid Production

et al. 2019

View full text Add to dashboard Cite

Streptomyces clavuligerus is a gram-positive filamentous bacterium notable for producing clavulanic acid (CA), an inhibitor of β-lactamase enzymes, which confers resistance to bacteria against several antibiotics. Here we present a comparative analysis of the morphological and metabolic response of S. clavuligerus linked to the CA production under low and high shear stress conditions in a 2D rocking-motion single-use bioreactor (CELL-tainer ®) and stirred tank bioreactor (STR), respectively. The CELL-tainer® guarantees high turbulence and enhanced volumetric mass transfer at low shear stress, which (in contrast to bubble columns) allows the investigation of the impact of shear stress without oxygen limitation. The results indicate that high shear forces do not compromise the viability of S. clavuligerus cells; even higher specific growth rate, biomass, and specific CA production rate were observed in the STR. Under low shear forces in the CELL-tainer® the mycelial diameter increased considerably (average diameter 2.27 in CELL-tainer® vs. 1.44 µm in STR). This suggests that CA production may be affected by a lower surface-to-volume ratio which would lead to lower diffusion and transport of nutrients, oxygen, and product. The present study shows that there is a strong correlation between macromorphology and CA production, which should be an important aspect to consider in industrial production of CA.

show abstract

“…When using molasses as substrate, keeping the RQ to a value of 1 during the cultivation aims to maintain metabolism in a state optimised for biomass formation [30]. During the propagation process, the RQ can be calculated and recorded online, based on oxygen and CO 2 content in the outlet gas, measured by gas analysis [31].…”

Section: Introductionmentioning

confidence: 99%

Novel Propagation Strategy of Saccharomyces cerevisiae for Enhanced Xylose Metabolism during Fermentation on Softwood Hydrolysate

Dobrescu

Veras²,

Varrone

et al. 2021

Fermentation

View full text Add to dashboard Cite

An economically viable production of second-generation bioethanol by recombinant xylose-fermenting Saccharomyces cerevisiae requires higher xylose fermentation rates and improved glucose–xylose co-consumption. Moreover, xylose-fermenting S. cerevisiae recognises xylose as a non-fermentable rather than a fermentable carbon source, which might partly explain why xylose is not fermented into ethanol as efficiently as glucose. This study proposes propagating S. cerevisiae on non-fermentable carbon sources to enhance xylose metabolism during fermentation. When compared to yeast grown on sucrose, cells propagated on a mix of ethanol and glycerol in shake flasks showed up to 50% higher xylose utilisation rate (in a defined xylose medium) and a double maximum fermentation rate, together with an improved C5/C6 co-consumption (on an industrial softwood hydrolysate). Based on these results, an automated propagation protocol was developed, using a fed-batch approach and the respiratory quotient to guide the ethanol and glycerol-containing feed. This successfully produced 71.29 ± 0.91 g/L yeast with an average productivity of 1.03 ± 0.05 g/L/h. These empirical findings provide the basis for the design of a simple, yet effective yeast production strategy to be used in the second-generation bioethanol industry for increased fermentation efficiency.

show abstract

An Online Respiratory Quotient-Feedback Strategy of Feeding Yeast Extract for Efficient Arachidonic Acid Production by Mortierella alpina

Cited by 9 publications

References 44 publications

Continuous Self-Cycling Fermentation Leads to Economical Lycopene Production by Saccharomyces cerevisiae

Continuous Self-Cycling Fermentation Leads to Economical Lycopene Production by Saccharomyces cerevisiae

Characterization of the Metabolic Response of Streptomyces clavuligerus to Shear Stress in Stirred Tanks and Single-Use 2D Rocking Motion Bioreactors for Clavulanic Acid Production

Novel Propagation Strategy of Saccharomyces cerevisiae for Enhanced Xylose Metabolism during Fermentation on Softwood Hydrolysate

Contact Info

Product

Resources

About